The invention relates to contactless rotary joints and, in particular, the contactless rotary joints adapted for use in CT scanners. In general, these contactless rotary joints have at least one inductive power coupler configured to transfer power at high levels and a high-speed data link for broadband transmission of data.
A contactless rotary joint with an inductive power coupler and a bidirectional high-speed data link is disclosed in U.S. Pat. No. 7,717,619 B2. Such a rotary joint is able to transfer power of more than hundred kilowatts and data in the 10 Gbit/s range. Due to the high level of power coupled by the inductive power coupler, which is based on a rotating transformer, there may be interference to the data link. Such interference may lead to data loss or even to a complete failure of the data link. To reduce the interference, preferably the magnetic cores of the rotating transformer are E-shaped and have differential windings. As power-level requirements and data rates are increasing further, the risk of interference increases. When the power level in the rotating transformer and, therefore, the stray fields increase, the bandwidth and therefore the sensitivity of the data link also increases.